CN105718658A - Large-size bridge online evaluating system - Google Patents

Abstract

The invention discloses a large-size bridge online evaluating system which comprises an evaluating unit model and an assessment system, wherein the evaluating unit model is used for establishing an examination assessment model; the examination assessment model comprises an evaluation management unit layer, a part layer, a member layer, a component layer and an evaluation index layer; the assessment system is used for ranking and assessing road bridges according to the information of the evaluation index layer, used for evaluating components according to evaluation scales of evaluation indexes, used for evaluating members, used for evaluating parts, and finally used for evaluating states of evaluation management units. According to the large-size bridge online evaluating system, an online evaluator which is applicable to automatic monitoring data as input is designed for specific bottom layer evaluation indexes, component evaluation indexes are widened so as to cover a great number of monitoring data and conventional manual detection data, and thus relatively comprehensive and accurate online evaluation on large bridges can be implemented.

Description

Large bridge online evaluation system

Technical field

The present invention relates to construction site detection field, relate in particular to a kind of large bridge online evaluation system.

Background technology

At present, to the assessment of large bridge according to from specification " Highway bridge technique status assessment standard " (JTG/TH21-2011, hereinafter referred to as " evaluation criteria "), it is applicable to the bridge technology status assessment to highways at different levels, and method is the method that layering Comprehensive Assessment controls to combine with single index.But in this specification, the evaluation index of all components derives from traditional manual detection (the apparent disease inspection of routine, periodic detection and special detection) result.

And along with the development of bridge structure automated monitoring technology, traditional based on routine testing maintenance work basis manually, the important large bridge of China substantially all establishes structure monitoring system, according to incompletely statistics, current having is mounted with structure monitoring system more than 200 Longspan Bridges.The magnanimity Monitoring Data that these operation phases produce, has trackability, objectivity, data volume greatly, and the features such as accuracy is good, are the high-quality Data Sources of large bridge safety and judging technical state.The final purpose of structure monitoring assessment is to set the tone for structural safety, for economical analysis of highway maintenance service.Current problem is in that how applying Monitoring Data carries out accurate and effective assessment.

In order to effectively apply Monitoring Data, structure is estimated, current existing many scholars have carried out research and the application of each side, it is main study subject as Li Aiqun and Research Team Yi Run thereof raises Yangtze Bridge monitoring mass data, the analysis of study emphasis bridge monitoring mass data and evaluation studies, king etc. proposes online structural analysis and the state evaluating method of bridge monitoring system.These methods are analyzed mainly by the mass data monitored and process, the evaluation index of extraction is analyzed result by the methods such as fuzzy reasoning, expert assessment and evaluation system, neutral net, Reliability Theory and structural finite element model or structure original state contrasts, so that it is determined that structural health or carry out non-destructive tests.But there is presently no the inspection evaluating system being specifically intended for on-line monitoring large bridge.

Summary of the invention

For the problems referred to above, it is an object of the invention to provide a kind of large bridge online evaluation system, to solve the problems of the prior art.

To achieve these goals, technical scheme is as follows:

Large bridge online evaluation system, it is characterised in that including:

Assessment model of element is set up, and is used for setting up inspection Evaluation model, and described inspection Evaluation model comprises assessment elementary layer, position layer, component layer, components layer and evaluation index layer；Described assessment elementary layer includes several assessment unit that can be independent；Described evaluation index layer includes visual examination disease class evaluation index, manual detection data class evaluation index and automatic monitoring data class evaluation index, and adopts least favorable principle to ensure the accuracy of indicator layer scale；Described automatic monitoring data class evaluation index is obtained by the sensor being set in advance in components layer；

Evaluation system, for carrying out grade assessment according to described evaluation index layer information to described highway bridge；Wherein, visual examination disease class evaluation index, manual detection data class evaluation index are obtained by manual detection method and mark according to national standard, automatic monitoring data class evaluation index is marked according to online evaluation device, then each component is estimated by the assessment scale according to each evaluation index, again each parts are estimated, again position is estimated, finally carries out the assessment of each assessment unit overall state.

In a preferred embodiment of the invention, described online evaluation device is according to after in the assessment period, the corresponding all Monitoring Data of index are analyzed process, online evaluation device is selected to mark, the assessment scale of index evaluation scale table agriculture products is pressed further according to point value of evaluation, the assessment algorithm of evaluation index layer can constantly extend, and described online evaluation device selects Reliability assessment device or degree of membership evaluator.

In a preferred embodiment of the invention, large bridge rationally carries out by frame mode being divided into each administrative unit, sets up assessment models for each administrative unit and is estimated, so can accurate evaluation and provide targetedly reasonable maintenance suggestion.

In a preferred embodiment of the invention, evaluation system is modular, and weight can determine benchmark weight according to specification or expert graded, then adopts according to indicator layer score and becomes power algorithm correction.

In a preferred embodiment of the invention, least favorable principle is adopted to ensure the accuracy of indicator layer scale, when manual detection index is the same with automatic monitoring index, according to least favorable principle, maximum one of label taking angle value.

In a preferred embodiment of the invention, it is possible to statistics is with type component technology situation, and statistical result is used for instructing maintenance.

In a preferred embodiment of the invention, evaluation system external disease countermeasure storehouse, there is the Maintenance Decision making effectively instructing maintenance unit for different assessment results.

In a preferred embodiment of the invention, the indicator layer of component can flexible expansion, span centre degree of disturbing, structural strain, bridge floor wind load, this is the index item to existing specification is important supplementing.

In a preferred embodiment of the invention, evaluation system band benchmark model, same operating mode, detection data regular, the currently monitored enter benchmark model, through finite element analysis, two second inner force distributions of structure can be obtained, there is obvious mechanical meaning, it is possible to directly refer to the weak link of derived type structure, future orientation maintenance work.

In a preferred embodiment of the invention, described Reliability assessment device, first determine the drag value of evaluation index, the i.e. evaluation criteria of such index, then according to drag value with by the calculated index mean value computation Low confidence limit of Monitoring Data, and parameter assesses mark f (β) further, so that it is determined that index evaluation scale.

In a preferred embodiment of the invention, described degree of membership evaluator is by arranging rational space partition zone threshold value, and namely fuzzy indicator a, b, c, d and input, output membership function, mark to automatic monitoring data class evaluation index.

In a preferred embodiment of the invention, described automatic monitoring data class evaluation index includes span centre degree of disturbing, pier sedimentation, structure temperature.

In a preferred embodiment of the invention, described visual examination disease class evaluation index includes voids and pits, peeling arrisdefect, cavity hole.

In a preferred embodiment of the invention, described manual detection data class evaluation index includes protective layer thickness, reinforcement corrosion, concrete carbonization, concrete strength, structure position changing, prestressed component damages, crack exists.

The present invention is on the basis of existing evaluation, formulate the rule of the assessment unit that large bridge is divided into some stress independence by version, then to be layered comprehensive estimation method for guiding principle, specific bottom evaluation index is devised and can be suitable for the online evaluation device that Monitoring Data is input.Component evaluation index has been expanded by this system, makes component evaluation index contain magnanimity Monitoring Data and traditional manual detection data, thus carrying out online evaluation more comprehensively, accurately to large bridge.The assessment result drawn through this system is accurate, objective, reasonable.

The feature of the present invention see graphic and better embodiment below the detailed description of this case and obtains and be well understood to.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of the present invention.

Fig. 2 is assessment dividing elements schematic diagram.

Fig. 3 is pier sedimentation, mid-span deflection and structure temperature point layout schematic diagram.

Fig. 4 is assessment situation schematic diagram.

Fig. 5 is membership function schematic diagram.

Fig. 6 is degree of membership assessment algorithm flow process and detailed description.

Detailed description of the invention

For the technological means making the present invention realize, creation characteristic, reach purpose and effect and be easy to understand, the present invention is expanded on further below in conjunction with specific embodiment.

Referring to Fig. 1, for certain Concrete Continuous Box Beam:

Large bridge online evaluation system, including:

Assessment model of element is set up, and is used for setting up inspection Evaluation model, and described inspection Evaluation model comprises assessment elementary layer, position layer (superstructure, substructure and bridge deck), component layer, components layer and evaluation index layer；As shown in Figure 2.About the division of assessment unit, for large bridge, the number of components is numerous, wants reach accurate evaluation and provide reasonable maintenance suggestion targetedly, it is necessary to overall bridge structure is carried out classifying rationally.Come from the theory of electronization, gridding, efficient maintenance management, with an independent and complete stress for principle, by version, large bridge is divided into some assessment unit, and usual one can assess unit as one across simply supported beam, a continuous beam, a steel structure, a cable-stayed bridge.

Evaluation index layer includes visual examination disease class evaluation index, manual detection data class evaluation index and automatic monitoring data class evaluation index；Automatic monitoring data class evaluation index includes span centre degree of disturbing, pier sedimentation, structural strain.Visual examination disease class evaluation index includes voids and pits, peels off arrisdefect, empty hole etc..Manual detection data class evaluation index includes protective layer thickness, reinforcement corrosion, concrete carbonization, concrete strength, structure position changing, prestressed component damage, crack etc..Automatic monitoring data class evaluation index is obtained by the sensor being set in advance in components layer.

Evaluation system, for carrying out grade assessment according to described evaluation index layer information to described highway bridge；Wherein, visual examination disease class evaluation index, manual detection data class evaluation index are obtained by manual detection method and mark according to national standard, when being estimated unit online evaluation, can read each index the last time testing result, it is estimated by evaluation criteria, it is determined that the assessment scale classification of index.Automatic monitoring data class evaluation index then needs according to after in the assessment period, the corresponding all Monitoring Data of index are analyzed process, suitable online evaluation device (such as Reliability assessment device, degree of membership evaluator) is selected to mark, further according to the point value of evaluation (hundred-mark system) the assessment scale by index evaluation scale table agriculture products.Then each component is estimated by the assessment scale according to each evaluation index, more each parts are estimated, then position is estimated, and is finally estimated the assessment of unit overall state.

Online evaluation device is according to after in the assessment period, the corresponding all Monitoring Data of index are analyzed process, select suitable online evaluation device Reliability assessment device or degree of membership evaluator to mark, press the assessment scale of index evaluation scale table agriculture products further according to point value of evaluation.

About Reliability assessment device, the quantity of reliability describes general reliability, reliability be structure within the time specified, when specifying, complete the probability of predetermined function.The determiner of reliability is component global resistance and load effect, and these factors are further divided into the variability etc. of material property ambiguity, component physical dimension ambiguity, model uncertainty and load assignment.In practical structures, affect member reliability because of usually for multiple stochastic variables.In bridge monitoring system, Sensor monitoring data include strain, displacement, temperature, wind speed etc., add up its regularity of distribution and be mostly normal distribution or logarithm normal distribution, therefore these monitoring projects can be considered as affecting the evaluation index of member reliability, adopt Reliability assessment device to be estimated.In Practical Project, during application Reliability assessment device, need to first determine the drag value (i.e. the evaluation criteria of such index) of evaluation index, then according to drag value with by the calculated index mean value computation Low confidence limit of Monitoring Data, and parameter assesses mark f (β) further, so that it is determined that index evaluation scale.

Reliability assessment need to give the drag value μ of evaluation index_R, evaluation process is as follows:

1, evaluation index mean μ within the assessment period is calculated_SWith coefficient of variation C (C=standard deviation/average=σ_S/μ_S)；

2, Low confidence limit is calculated

$\mathrm{\β}=({\mathrm{\μ}}_R-{\mathrm{\μ}}_S)/\left\{C{({\mathrm{\μ}}_R^2+{\mathrm{\μ}}_S^2)}^{1/2}\right\}$

3, evaluation index score f (β) is calculated

$f\left(\mathrm{\β}\right)=\frac{1}{\sqrt{2\mathrm{\π}}}{\∫}_{-\mathrm{\∞}}^{\mathrm{\β}-\frac{1}{\sqrt{13}C}}{e}^{-\frac{t^2}{2}}dt$

4, table look-up according to evaluation index score obtain assessment scale value.

About degree of membership evaluator, in order to solve the uncertain problem of index standards of grading, domestic and international many scholars propose scoring theoretical based on fuzzy reasoning, be estimated index by the method for statistical analysis agriculture products membership function.This class index evaluation device is referred to as degree of membership evaluator, when practical application, depending on index concrete condition, by arranging rational space partition zone threshold value (i.e. fuzzy indicator a, b, c, d) with input, output membership function, evaluation index is marked, such as the fuzzy inference system (thefuzzyinferencesystem) that light red brightness proposes in Donghai Bridge monitoring system.

Degree of membership assessment algorithm illustrates as follows:

1, membership function principle

The matching of membership function is to adopt Cauchy distribution, and its main Types has following three kinds, as shown in Figure 5.

(1) Fuzzy less than normal distribution, x is more big, then degree of membership is more little, adopts and drops half Cauchy distribution

${\mathrm{\μ}}_1\left(x\right)=\left\{\begin{array}{cc}1& x\≤a\\ \frac{1}{1+\mathrm{\α}{(x-a)}^{\mathrm{\β}}}& x>a\end{array}\right.---\left(1.1\right)$

(2) middle type Fuzzy Distribution, adopts symmetrical Cauchy distribution

${\mathrm{\μ}}_2\left(x\right)=\frac{1}{1+\mathrm{\α}{(x-a)}^{\mathrm{\β}}}---\left(1.2\right)$

(3) Fuzzy bigger than normal distribution, x is more big, then degree of membership is more big, adopts and rises half Cauchy distribution

${\mathrm{\μ}}_3\left(x\right)=\left\{\begin{array}{cc}0& x\≤a\\ \frac{1}{1+\mathrm{\α}{(x-a)}^{-\mathrm{\β}}}& x>a\end{array}\right.---\left(1.3\right)$

In formula: α and β is parameter, and there is α > 0, β > 0.

Specific to four functions of D, C, B, A of classification, it is respectively adopted the functional form of (1.4), (1.5), (1.6), (1.7).Wherein β takes 2.

That is:

${\mathrm{\μ}}_D\left(x\right)=\left\{\begin{array}{cc}1& x\≤a_1\\ \frac{1}{1+{\mathrm{\α}}_1{(x-a_1)}^2}& x>a_1\end{array}\right.---\left(1.4\right)$

${\mathrm{\μ}}_C\left(x\right)=\frac{1}{1+{\mathrm{\α}}_2{(x-a_2)}^2}---\left(1.5\right)$

${\mathrm{\μ}}_B\left(x\right)=\frac{1}{1+{\mathrm{\α}}_3{(x-a_3)}^2}---\left(1.6\right)$

${\mathrm{\μ}}_A\left(x\right)=\left\{\begin{array}{cc}0& x\≤a_4\\ \frac{1}{1+{\mathrm{\α}}_4{(x-a_4)}^{-2}}& x>a_4\end{array}\right.---\left(1.7\right)$

As long as it appears from the above, in fact determining a₁、a₂、a₃、a₄And α₁、α₂、α₃、α₄8 unknown numbers have determined that 4 membership functions.

Assume that corresponding step scale is:

D	C	B	A
				x≤g1	g1< x≤g2	g2< x≤g3	g3< x

So, g₁、g₂、g₃And a₁、a₂、a₃、a₄Meet following relation:

a₁≈0.8g₁

$a_2=\frac{(g_1+g_2)}{2}$

$a_3=\frac{(g_2+g_3)}{2}$

$a_4=\frac{(g_2+3g_3)}{4}$

And α₁、α₂、α₃、α₄And a₁、a₂、a₃、a₄Meet again following relation:

${\mathrm{\α}}_1=\frac{2}{{(g_1-a_1)}^2}$

${\mathrm{\α}}_2=\frac{2}{{(g_1-a_2)}^2}$

${\mathrm{\α}}_3=\frac{2}{{(g_2-a_3)}^2}$

α₄=2* (g₃-a₄)²

Thus can determine all 8 parameters by three step scales.

2, algorithm flow and detailed description, as shown in Figure 6.

2.1 membership function parameters

Index x divides four to judge grade A, B, C, D (all indexs are all by four grade classification), and Classification Indexes at different levels are g₁、g₂、g₃(evaluation index provides when setting), as shown in the table

D	C	B	A
				x≤g1	g1< x≤g2	g2< x≤g3	g3< x

Then membership function parameter a₁、a₂、a₃、a₄And α₁、α₂、α₃、α₄It is calculated as follows:

a₁≈0.8g₁

$a_2=\frac{(g_1+g_2)}{2}$

$a_3=\frac{(g_2+g_3)}{2}$

$a_4=\frac{(g_2+3g_3)}{4}$

${\mathrm{\α}}_1=\frac{2}{{(g_1-a_1)}^2}$

${\mathrm{\α}}_2=\frac{2}{{(g_1-a_2)}^2}$

${\mathrm{\α}}_3=\frac{2}{{(g_2-a_3)}^2}$

α₄=2* (g₃-a₄)²

2.2 each membership functions

After obtaining membership function parameter, corresponding for index x each membership function can be sought by following several calculating formulas:

${\mathrm{\μ}}_D\left(x\right)=\left\{\begin{array}{cc}1& x\≤a_1\\ \frac{1}{1+{\mathrm{\α}}_1{(x-a_1)}^2}& x>a_1\end{array}\right.---\left(1.4\right)$

${\mathrm{\μ}}_C\left(x\right)=\frac{1}{1+{\mathrm{\α}}_2{(x-a_2)}^2}---\left(1.5\right)$

${\mathrm{\μ}}_B\left(x\right)=\frac{1}{1+{\mathrm{\α}}_3{(x-a_3)}^2}---\left(1.6\right)$

${\mathrm{\μ}}_A\left(x\right)=\left\{\begin{array}{cc}0& x\≤a_4\\ \frac{1}{1+{\mathrm{\α}}_4{(x-a_4)}^{-2}}& x>a_4\end{array}\right.---\left(1.7\right)$

2.3 index evaluation values and assessment mark

Degrees of membership at different levels corresponding for index x are normalized after obtaining, and obtain

A={ μ_Aμ_Bμ_Cμ_D}

Then corresponding for index x assessed value is F=A* [4321]^T=μ_A*4+μ_B*3+μ_C*2+μ_D*1

The assessment mark H=100-12.5F of index x

Donghai Bridge engineering is the important conveyance system of Shanghai International Shipping Center the first phase project of Yangshan Deep water Port, and total length is about 31km.Donghai Bridge engineering mainly includes steel box girder stayed-cable bridge, large span uprises prestressed concrete continuous box girder and the height continuous box girder three major types version such as 30～70m prestressed concrete, according to assessment dividing elements rule, bridge is totally divided into 182 assessment unit, and wherein 8 assessment unit are provided with and monitor sensor in real time.As space is limited, it is provided with the assessment unit 160m of monitoring in real time across pair navigation bridge herein for one of them, with the prison detection data of its in December, 2014 for assessment Data Source, the large bridge online evaluation system based on " Highway bridge technique status assessment standard " is adopted to be estimated by the software program module worked out.

160m is 90+160+160+90m And of Varying Depth prestressed concrete continuous beam across pair navigation bridge, except traditional manual detection project, Donghai Bridge monitoring system has laid hydrostatic level in the secondary navigable span centre position of this assessment unit each pier pier top and two, and select a pier top section to arrange anemobiagraph, at secondary navigable span centre section, structural strain meter is set, the monitoring pier sedimentation of this structural sections, mid-span deflection, structural strain, bridge floor wind load in real time, point layout is as shown in Figure 3.

According to monitoring situation, during the online evaluation system of this assessment unit is arranged, except the component evaluation index in evaluation criteria, in the girder TXL-002 and girder TXL-003 component of superstructure, increase " mid-span deflection ", " structural strain " and " wind load " evaluation index, adopt Reliability assessment device to carry out index scoring；And in all bridge pier components of substructure, increase " pier sedimentation " index, adopt degree of membership evaluator to carry out index scoring.Prison detection data according in December, 2014,160m is superstructure scoring 88.44 across pair navigation bridge online evaluation result, substructure scoring 82.54, bridge deck scoring 95.74, assessment unit TOP SCORES is 87.54, constructional aspect is two classes, slight defect has been described, but has used function without impact on bridge.Superstructure assessment situation is as shown in Figure 4.

The principle that evaluating system proposed by the invention is formulated in accordance with evaluation criteria, for large bridge, first according to the version in bridge, by independent stressed principle, is divided into some assessment unit by large bridge；Then the regulation according to evaluation criteria, determines the information such as component classification, assessment weight by assessment unit structural form；It is according to monitoring system point layout situation again, determines component evaluation index and evaluation criteria (including Monitoring Data class evaluation index, such index need to determine suitable online evaluation device and evaluation criteria targetedly, sees below) in conjunction with evaluation criteria；Each assessment unit is estimated by method one by one that finally control to combine with single index by layering comprehensive assessment.This evaluation system uses for reference the distinguishing hierarchy principle of evaluation criteria, recursive rule between appraisal framework and level is all by the requirement of evaluation criteria, but component evaluation index has been expanded, making component evaluation index contain automatic monitoring data and traditional manual detection data, the large bridge judging technical state for built vertical monitoring system provides reference.This evaluation system has passed through the corresponding software module of establishment and realizes on-line automatic assessment in monitoring system, and in software module, authorized user can select suitable online evaluation device according to Monitoring Data feature, and the assessment result that bottom evaluation index and top layer can be assessed unit is modified, thus carrying out online evaluation more comprehensively, accurately to large bridge, it is achieved monitoring system is the purpose of bridge maintenance management decision-making service.

The ultimate principle of the present invention, principal character and advantages of the present invention have more than been shown and described.Skilled person will appreciate that of the industry; the present invention is not restricted to the described embodiments; simply principles of the invention described in above-described embodiment and description; the present invention also has various changes and modifications without departing from the spirit and scope of the present invention, and these changes and improvements both fall within claimed the scope of the present invention.The protection domain of application claims is defined by appending claims and equivalent thereof.

Claims (14)

1. large bridge online evaluation system, it is characterised in that including:

Large bridge is made up of several assessment unit, and assessment model of element is set up, and is used for setting up inspection Evaluation model, and described inspection Evaluation model comprises assessment elementary layer, position layer, component layer, components layer and evaluation index layer；Described evaluation index layer includes visual examination disease class evaluation index, manual detection data class evaluation index and automatic monitoring data class evaluation index, and adopts least favorable principle to ensure the accuracy of indicator layer scale；Described automatic monitoring data class evaluation index is obtained by the sensor being set in advance in components layer.

Evaluation system, for carrying out grade assessment according to described evaluation index layer information to described highway bridge；Wherein, visual examination disease class evaluation index, manual detection data class evaluation index are obtained by manual detection method and mark according to national standard, automatic monitoring data class evaluation index is marked according to online evaluation device, then each component is estimated by the assessment scale according to each evaluation index, again each parts are estimated, again position is estimated, is finally estimated the assessment of unit overall state.

2. Highway bridge technique situation according to claim 1 checks evaluating system, it is characterized in that, described online evaluation device is according to after in the assessment period, the corresponding all Monitoring Data of index are analyzed process, online evaluation device is selected to mark, the assessment scale of index evaluation scale table agriculture products is pressed further according to point value of evaluation, the assessment algorithm of evaluation index layer can constantly extend, and described online evaluation device selects Reliability assessment device or degree of membership evaluator.

3. large bridge online evaluation system according to claim 1, it is characterised in that rationally carry out large bridge by frame mode being divided into each administrative unit, set up assessment models for each administrative unit and be estimated.

4. large bridge online evaluation system according to claim 1, it is characterised in that evaluation system is modular, and weight can determine benchmark weight according to specification or expert graded, then adopts according to indicator layer score and becomes power algorithm correction.

5. large bridge online evaluation system according to claim 1, it is characterised in that adopt least favorable principle to ensure the accuracy of indicator layer scale, when manual detection index is the same with automatic monitoring index, according to least favorable principle, maximum one of label taking angle value.

6. large bridge online evaluation system according to claim 1, it is characterised in that can adding up same type component technology situation, statistical result is used for instructing maintenance.

7. large bridge online evaluation system according to claim 1, it is characterised in that evaluation system external disease countermeasure storehouse, has the Maintenance Decision making effectively instructing maintenance unit for different assessment results.

8. large bridge online evaluation system according to claim 1, it is characterised in that the indicator layer of component can flexible expansion, be important supplementing to the index item of specification, such as span centre degree of disturbing, structural strain, bridge floor wind load.

9. large bridge online evaluation system according to claim 1, it is characterized in that, evaluation system band benchmark model, same operating mode, detection data regular, the currently monitored enter benchmark model, through finite element analysis, it is possible to obtain two second inner force distributions of structure, there is obvious mechanical meaning, can directly refer to the weak link of derived type structure, future orientation maintenance work.

10. large bridge online evaluation system according to claim 2, it is characterized in that, described Reliability assessment device, first determine the drag value of evaluation index, the i.e. evaluation criteria of such index, then according to drag value with by the calculated index mean value computation Low confidence limit of Monitoring Data, and parameter assesses mark f (β) further, so that it is determined that index evaluation scale.

11. large bridge online evaluation system according to claim 2, it is characterised in that described degree of membership evaluator is by arranging rational space partition zone threshold value, i.e. fuzzy indicator a, b, c, d and input, output membership function, mark to automatic monitoring data class evaluation index.

12. large bridge online evaluation system according to claim 1, it is characterised in that described automatic monitoring data class evaluation index includes span centre degree of disturbing, structural strain, bridge floor wind load.

13. large bridge online evaluation system according to claim 1, it is characterised in that described visual examination disease class evaluation index includes voids and pits, peeling arrisdefect, cavity hole.

14. large bridge online evaluation system according to claim 1; it is characterized in that, described manual detection data class evaluation index includes protective layer thickness, reinforcement corrosion, concrete carbonization, concrete strength, structure position changing, prestressed component damage, crack.